Starch is composed of two distinct polymer fractions: amylose and amylopectin. Amylose is the linear fraction consisting of .alpha.-1,4 linked glucose units. Amylopectin has the same structure as amylose but some of the glucose units are combined in an .alpha.-1,6 linkage giving rise to a branched structure. Starches generally contain 17-24% amylose and from 76-83% amylopectin.
Special genetic varieties of plants have been discovered or developed which produce starch with unusual amylose to amylopectin ratios. Some plants produce starch that is free of amylose. These mutants produce starch granules in the endosperm and pollen which stain red with iodine and which contain nearly 100% amylopectin. Predominant among such amylopectin producing plants are waxy corn, waxy sorghum and waxy rice starch.
Regurgitation of infant formula by infants is a common problem. The addition of certain thickening agents to infant formulas is known in the art to be effective in reducing the incidence and/or severity of regurgitation. Examples of thickening agents known in the art include rice cereal (see, Ramenofsky, M. L., et al, J. Pediatr. Surg, 1981; 16:374-378) and seed gums like carob bean gum (see, Vandenplas, Y., et al, Clin. Pediatics, 1987; 26(2):66-68; European Patent 0611524).
Commercial products are Frisovom from Friesland Frico Domo and Nutrilon AR from Nutricia which contain locust bean gum as a thickening agent.
It has been discovered that use of potato starch or certain high amylopectin containing grain starches in infant formulas provides advantages heretofore unachievable.